Florida's lieutenant governor has resigned and 57 people have been charged amid a $300 million gambling operation allegedly masked as a veterans charity.

"Operation Reveal the Deal uncovered a sophisticated racketeering and money laundering scheme stemming from 49 illegal gambling centers operating under the guise of 'internet cafes,'" investigators wrote in a statement. "The organization falsely claimed to be a charitable veterans' organization, but instead deceived the public and government while lining the pockets of its operators."

Of the $300 million in proceeds from the gambling centers run by a purported non-profit called Allied Veterans of the World, only 2 percent of the money went to charitable organizations, according to police.

"It's callous and despicable," Florida Attorney General Pam Bondi said at a news conference. "Claiming to be an organization designed to help veterans in order to run an illegal scheme insults every American who ever wore a military uniform."

A joint statement by the local, state and federal authorities said, "Investigators allege it ran gambling centers and illegal slot machines, funnelling the illegal proceeds through a sophisticated web of for-profit corporations that paid off the Allied Veterans of the World management, software provider and lawyer."

Slot machines and records have been seized from the organization as well as 80 vehicles and vessels, 170 properties and 260 bank accounts estimated in the tens of millions of dollars, investigators said.

The phone for Allied Veterans of the World, which is federally registered as a tax-exempt veterans organization that operates for charitable purposes, have been disconnected and the organization did not respond to emails.

The three-year local, state and federal investigation spanned six states--Florida, Alabama, South Carolina, Pennsylvania, Nevada and Georgia.

In some places, the gambling cafes are legal as long as the majority of the profits are donated to charity. Patrons played gambling games on computers and slot machines at the cafes.

Florida's Lt. Gov. Jennifer Carroll submitted a two-sentence resignation Tuesday to Gov. Rick Scott the day after she was questioned in the investigation. She has not been accused of any wrongdoing, but consulted for the purported charity in 2009 and 2010 when she was a state representative and ran a public relations firm. She even appeared in a commercial for the organization.

Carroll, 53, is a military veteran who served 20 years in the Navy and in the Gulf War. She was chosen as Gov. Scott's running mate in 2010. She represented Florida on the floor of the Republican National Convention in 2012 when Gov. Mitt Romney was nominated as the Republican candidate.

Carroll said in a statement that she has and will fully cooperate with the investigation and does not believe that she or her company are targets of the investigation.

"I simply refuse to allow the allegations facing a former client of my public relations firm to undermine the important work of the governor and his administration," she wrote.

Gov. Scott refused to talk about the investigation, but supported Carroll's decision to resign.

"I will not elaborate on the details of her resignation further, other than to say that she resigned and she made the right decision for the state and her family," Scott said.

So far, 49 of the 57 people charged in the scam have been arrested, including the group's "four co-conspirators," police said. The four leaders allegedly pocketed more than $90 million.

Formal charges are expected to be filed next week and the charges include money laundering, racketeering, conspiracy and possession of slot machines, Bondi said.